THE NORTHERN LEG OF THE DOWNTOWN LOOP: In its 1960 master highway plan, the Montreal Metropolitan Committee proposed a new seven-kilometer (4.3-mile)-long autoroute along the city's east-west street grid at the northern edge of downtown. The six-lane autoroute, which was forecast to handle as many as 4,500 vehicles per hour during weekday peak periods, was to form part of a downtown expressway loop that included the Decarie (A-15), Ville Marie (A-720), and Papineau (A-19) autoroutes.

A TUNNEL BENEATH MOUNT ROYAL PARK: Beginning at the Decarie Autoroute at Monkland Avenue in the Notre-Dame-de-Grace section of the city (at the current EXIT 66 on A-15), the Mount Royal Autoroute was to extend in a northeasterly direction through Westmount toward Mount Royal Park. It likely would have tunneled for about three kilometers (1.8 miles) beneath the park and the highest point in the city (the 234-meter / 768-foot Mount Royal) before emerging above ground at Rachel Street. The Mount Royal Autoroute would have extended along Rachel Street to the Papineau Autoroute, which was to have been built south from Laval toward the Jacques Cartier Bridge.

The Mount Royal Autoroute was part of a C$288 million proposal to build an east-west highway and a north-south highway tunnel (whose alignment was shifted east toward the Papineau Avenue / A-19 corridor before that section ultimately was canceled). The costs of building not only an expressway through an urban area, but also a long tunnel beneath Mount Royal Park - which would have been an engineering challenge because of the presence of an existing north-south railroad tunnel through the park - likely killed the Mount Royal Autoroute before the end of the 1960's. If the six-lane autoroute had been built, it likely would have received the A-415 designation to denote its significance as a loop route.

SOURCE: "Volume of Traffic for the Proposed Expressway System, Based on Projections for the Year 1981," Ville de Montreal, Service de la Circulation (1961); "A Study of the Existing Montreal Expressway System" by Dominic Mignogna, McGill University (1969); "City of Lost Dreams" by Kristian Gravenor, The Montreal Mirror (10/26/2000).